This American Diet

Western-style diet may contribute to increased risk of kidney dysfunction

(RxWiki News) Researchers at Brigham and Women's Hospital have found that the common Western diet - high in red meats, processed meats, saturated fats, and sweets - is related to a higher risk of decline in kidney function.

The study, which is the first to look at this relationship between diet and change in kidney function over time, examined the impact of three different diets on kidney function.

Those diets were a 1. Western diet (high in red and processed meats, saturated fats, and sweets); a 2. Prudent diet (high in fish, poultry, fruits, vegetables, and whole grains); and a 3. DASH-style diet (aka Dietary Approach to Stop Hypertension, a diet high in low-fat dairy, nuts, legumes, fruits, vegetables, and whole grains, but low in sweetened beverages).

The effects of these diets on kidney function was observed in 3,121 women over the course of 11 years. The researchers used two measures to determine kidney dysfunction: 1. estimated glomerular filtration rate (eGFR), a measure of the kidney's blood filtering abilities (low GFR indicates kidney disease), and 2. microalbuminuria, a urinary protein that, when present in high amounts, may be a sign of vascular disease and inflammation. Therefore low eGFR and high microalbuminuria are a bad sign.

The researchers found that women who had a Western diet tended to have higher levels of microalbuminuria and were more likely to have rapid eGFR decline. This findings reveal that a Western diet, which is already linked to a greater risk of cardiovascular disease, may also contribute to a decline in kidney function over time. Conversely, a diet high in whole grains, fruits, and vegetables may slow the progress of kidney dysfunction.

According to Julie Lin, M.D., M.P.H., a physician in the Renal Division of Brigham and Women's Hospital and lead author of the study, the higher levels of albuminuria found in those with a Western diet show that albuminuria may be more than a marker for vascular disease. The study's findings suggest they may be influenced by diet.

The authors realize that one of the drawbacks of their study is that it examined only women who were predominantly white. They acknowledge that further research must be conducted in order to understand the relationship between diet and change in kidney function over time in non-whites and men.

Approximately 26 million adults in the United States have chronic kidney disease, and millions more are at risk. Most of these people are unaware that they have kidney disease or have declining kidney function. The National Kidney Foundation urges high risk individuals (those with high blood pressure, diabetes, or a family history of kidney disease) to get tested. The National Kidney Foundation offers free screening for qualified individuals through there Kidney Early Evaluation Program (KEEP). Visit the National Kidney Foundation's website for more information (www.kidney.org).

This study appears online and in the February issue of the American Journal of Kidney Disease.

Review Date: 
February 2, 2011